From e2902e538a77ebdb21420f3905a20cdd28095909 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bel=C3=A9n=20Albeza?= <belen@hey.com>
Date: Fri, 19 Jul 2024 10:29:09 +0200
Subject: [PATCH] Add EQU and EQU2 opcodes

---
 coco-core/src/lib.rs     | 41 ++++++++++++++++++++++++++++++++++++++++
 coco-core/src/opcodes.rs |  2 ++
 2 files changed, 43 insertions(+)

diff --git a/coco-core/src/lib.rs b/coco-core/src/lib.rs
index 13f5717..9723b96 100644
--- a/coco-core/src/lib.rs
+++ b/coco-core/src/lib.rs
@@ -80,6 +80,8 @@ impl Cpu {
                 opcodes::INC => self.op_inc(),
                 opcodes::DUP => self.op_dup(),
                 opcodes::DUP2 => self.op_dup2(),
+                opcodes::EQU => self.op_equ::<0x00>(),
+                opcodes::EQU2 => self.op_equ::<FLAG_SHORT>(),
                 opcodes::JMP => self.op_jmp(),
                 opcodes::JMP2 => self.op_jmp2(),
                 opcodes::JNZ => self.op_jnz::<0x00>(),
@@ -181,6 +183,21 @@ impl Cpu {
         self.stack.push_short(value);
     }
 
+    #[inline]
+    fn op_equ<const FLAGS: u8>(&mut self) {
+        let res = if short_mode(FLAGS) {
+            let b = self.stack.pop_short();
+            let a = self.stack.pop_short();
+            a == b
+        } else {
+            let b = self.stack.pop_byte();
+            let a = self.stack.pop_byte();
+            a == b
+        };
+
+        self.stack.push_byte(if res { 0x01 } else { 0x00 });
+    }
+
     #[inline]
     fn op_jmp(&mut self) {
         let offset = self.stack.pop_byte();
@@ -653,4 +670,28 @@ mod tests {
         assert_eq!(cpu.stack.len(), 0);
         assert_eq!(cpu.ram_peek_short(0x01), 0xabcd);
     }
+
+    #[test]
+    fn equ_opcode() {
+        let rom = rom_from(&[PUSH, 0xab, PUSH, 0xab, EQU, PUSH, 0x00, EQU, BRK]);
+        let mut cpu = Cpu::new(&rom);
+
+        let pc = cpu.run(0x100, &mut AnyMachine {});
+
+        assert_eq!(pc, 0x109);
+        assert_eq!(cpu.stack.len(), 1);
+        assert_eq!(cpu.stack.byte_at(0), 0x00);
+    }
+
+    #[test]
+    fn equ2_opcode() {
+        let rom = rom_from(&[PUSH2, 0xab, 0xcd, PUSH2, 0xab, 0xcd, EQU2, BRK]);
+        let mut cpu = Cpu::new(&rom);
+
+        let pc = cpu.run(0x100, &mut AnyMachine {});
+
+        assert_eq!(pc, 0x108);
+        assert_eq!(cpu.stack.len(), 1);
+        assert_eq!(cpu.stack.byte_at(0), 0x01);
+    }
 }
diff --git a/coco-core/src/opcodes.rs b/coco-core/src/opcodes.rs
index 777b23b..5163e63 100644
--- a/coco-core/src/opcodes.rs
+++ b/coco-core/src/opcodes.rs
@@ -2,6 +2,8 @@ pub const BRK: u8 = 0x00;
 pub const INC: u8 = 0x01;
 pub const DUP: u8 = 0x06;
 pub const DUP2: u8 = 0x26;
+pub const EQU: u8 = 0x08;
+pub const EQU2: u8 = 0x28;
 pub const JMP: u8 = 0x0c;
 pub const JMP2: u8 = 0x2c;
 pub const JNZ: u8 = 0x0d;